How to debug - Python CTypes calling glibc * detection

I have compiled the C ++ program into a dynamic library which I now call in python via ctypes. However, I am getting the following error:

*** glibc detected *** ../../bin/python: free(): invalid pointer: 0x00007fbdf8ae3500 ***

      

        
        
        
      

    

How can I tell if this is a bug in the C ++ code or how am I using ctypes?

The C ++ library works successfully when linked with a C program, or if I compile it as a standalone program. Combined with ctypes, it always fails on this C ++ line:

// ... A bunch of code
if(tempBuffer) {
    delete[] tempBuffer;
    // More code below that never runs...

      

        
        
        
      

    

Failed to execute Python code:

def test(fileName):
    feedbackLib = cdll.LoadLibrary("./libpitch.so")

    # Set return type to a character pointer
    feedbackLib.getPitchString.restype = c_char_p
    feedbackLib.getPitchString.argtypes = [c_char_p]

    # Crashes Here!
    feedbackStr = feedbackLib.getPitchString(fileName)
    return feedbackStr

      

        
        
        
      

    

For some reason, I can get the python program to work successfully if I change things like this:

def test(fileName):
    # I've only changed this line
    feedbackLib = CDLL("./libpitch.so")

    # Set return type to a character pointer
    feedbackLib.getPitchString.restype = c_char_p
    feedbackLib.getPitchString.argtypes = [c_char_p]

    # No longer crashes!
    feedbackStr = feedbackLib.getPitchString(fileName)
    return feedbackStr 

      

        
        
        
      

    

However, if I start adding things to the above function (which I need to do) it gives me other glibc errors.

Here's information on how I compiled C ++ in case it matters.

The header of the function I am calling using extern "C" looks like how to get the C ++ code to work with CTypes:

extern "C" char* getPitchString(char* filename);

      

        
        
        
      

    

g ++:

$(CXX) $(LDFLAGS) -fPIC -c $(SRCS) $(LIBS)
$(CXX) -shared -Wl,-soname,libpitch.so -o libpitch.so $(OBJS) $(LIBS)